Liquids which under certain conditions have properties otherwise observed only with crystalline solids, such as optical anisotropy have been known for a long time. Likewise, compositions containing liquid-crystalline phases based on long-chained organopolysiloxanes having chemically bonded mesogenic groups have been described in German patent application No. 2,944,59l to Wacker Chemie GmbH. However, the conversion of long-chained organopolysiloxanes containing mesogenic groups into the liquid-crystalline state frequently presents difficulties, since prolonged heating or tempering times must be tolerated to reach a high degree of order. On the other hand, short-chained organopolysiloxanes having mesogenic groups actually do become oriented spontaneously, but they generally have undesirable adhesive properties.
Therefore, it is an object of this invention to provide compositions which have liquid-crystalline phases at relatively low temperatures. Another object of this invention is to prepare compositions having liquid-crystalline phases over a wide range of pressure and temperature. Still another object of this invention is to provide compositions having liquid-crystalline phases which can be tailored to the requirements of the particular application. A further object of this invention is to form compositions containing liquid-crystalline phases which are non-adhesive at ambient temperatures and after exceeding the glass transition temperature can be readily oriented; that is, converted into a liquid-crystalline state of high order.